package com.lhdx.practical.controllers;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

@Controller
public class ImageController {

    @RequestMapping(value = "/verificationcode", method = RequestMethod.GET)
    public ModelAndView loginPage(HttpServletRequest request,HttpServletResponse response) throws Exception{
        int width = 100;// 验证码图片宽度
        int height = 30;// 验证码图片高度
        BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_BYTE_GRAY);
        Graphics g = image.getGraphics();
        Random random = new Random();// 创建一个随机类
        g.setColor(getRandColor(200, 250));// 背景颜色要偏淡
        g.fillRect(0, 0, width, height);// 画背景
        g.setColor(getRandColor(0, 255));// 边框颜色
        g.drawRect(0, 0, width - 1, height - 1);// 画边框
        g.setColor(getRandColor(160, 200));// 随机产生5条干扰线，使图象中的认证码不易被其它程序探测到
        for (int i = 0; i < 8; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            g.drawLine(x, y, x1, y1);
        }
        g.setColor(getRandColor(160, 200));// 随机产生100点，使图象中的认证码不易被其它程序探测到
        for (int i = 0; i < 100; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            g.drawLine(x, y, x, y);
        }
        Font font = new Font("Times New Roman", Font.ITALIC, 26); // 创建字体，字体的大小应该根据图片的高度来定。
        g.setFont(font);// 设置字体
        int length = 4; // 设置默认生成4个验证码
        String s = "1234567890"; // 设置备选验证码:"0-9"
        String sRand = "";

        // 用随机产生的颜色将验证码绘制到图像中。
        // 生成随机颜色(因为是做前景，所以偏深)
        // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
        g.setColor(new Color(20 + random.nextInt(110),
                20 + random.nextInt(110), 20 + random.nextInt(110)));
        for (int i = 0; i < length; i++) {
            String ch = String.valueOf(s.charAt(random.nextInt(s.length())));
            sRand += ch;
            g.drawString(ch, 22 * i + 12, (random.nextInt(5) - 2) * i + 20);
        }
        // 将生成的字符串存储在session中
        HttpSession session = request.getSession();
        session.setAttribute("checkCode", sRand);

        //保存cookie
        //Cookie cookie = new Cookie("checkCode",sRand);
        //response.addCookie(cookie);

        g.dispose();// 图像生效
        // 禁止图像缓存
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("image/jpeg");
        // 创建二进制的输出流
        ServletOutputStream sos = response.getOutputStream();
        // 将图像输出到Servlet输出流中。
        ImageIO.write(image, "jpeg", sos);
        sos.flush();
        sos.close();
        return null;
    }

    private Color getRandColor(int lower, int upper) {
        Random random = new Random();
        if (upper > 255)
            upper = 255;
        if (upper < 1)
            upper = 1;
        if (lower < 1)
            lower = 1;
        if (lower > 255)
            lower = 255;
        int r = lower + random.nextInt(upper - lower);
        int g = lower + random.nextInt(upper - lower);
        int b = lower + random.nextInt(upper - lower);
        return new Color(r, g, b);
    }
}
